import 'package:ansu_ui/utils/city_util.dart'; import 'package:ansu_ui/pickers/as_picker_box.dart'; import 'package:flutter/cupertino.dart'; import 'package:flutter/material.dart'; import 'package:flutter_screenutil/flutter_screenutil.dart'; class ASCityPicker extends StatefulWidget { ASCityPicker({Key key}) : super(key: key); @override _ASCityPickerState createState() => _ASCityPickerState(); } class _ASCityPickerState extends State { double getFontSize(String text) { double fontSize = 13.sp; int len = text?.length ?? 0; if (len >= 1 && len <= 3) { fontSize = 20.w; } else if (len > 3 && len <= 4) { fontSize = 18.sp; } else if (len > 4 && len <= 5) { fontSize = 16.sp; } else if (len > 5 && len <= 6) { fontSize = 14.sp; } else if (len > 6 && len <= 9) { fontSize = 12.sp; } else if (len > 9) { fontSize = 8.sp; } return fontSize; } ProvinceModel _selectedProvince; CityModel _selectedCity; CityModel _selectedDistrict; FixedExtentScrollController _cityController = FixedExtentScrollController(); FixedExtentScrollController _districtController = FixedExtentScrollController(); @override void initState() { super.initState(); _selectedProvince = CityUtil.provinceModel.first; _selectedCity = CityUtil.getCityModelByCode(_selectedProvince.code).first; _selectedDistrict = CityUtil.getCityModelByCode(_selectedCity.code).first; } @override void dispose() { _cityController?.dispose(); super.dispose(); } @override Widget build(BuildContext context) { return ASPickerBox( onPressed: () { Navigator.pop(context, _selectedDistrict); }, child: Row( children: [ Expanded( child: CupertinoPicker( offAxisFraction: -0.6, itemExtent: 30, useMagnifier: true, magnification: 1.1, onSelectedItemChanged: (value) { _cityController.animateToItem( 0, duration: Duration(milliseconds: 300), curve: Curves.ease, ); _districtController.animateToItem( 0, duration: Duration(milliseconds: 300), curve: Curves.ease, ); setState(() { _selectedProvince = CityUtil.provinceModel[value]; _selectedCity = CityUtil.getCityModelByCode(_selectedProvince.code).first; _selectedDistrict = CityUtil.getCityModelByCode(_selectedCity.code).first; }); }, children: CityUtil.provinceModel .map((e) => Center( child: Text( e.name, style: TextStyle( fontSize: getFontSize(e.name), ), ))) .toList(), looping: true, ), ), Expanded( child: CupertinoPicker( looping: CityUtil.getCityModelByCode(_selectedProvince.code).length > 1, scrollController: _cityController, itemExtent: 30, useMagnifier: true, magnification: 1.1, onSelectedItemChanged: (value) { _districtController.animateToItem( 0, duration: Duration(milliseconds: 300), curve: Curves.ease, ); setState(() { _selectedCity = CityUtil.getCityModelByCode( _selectedProvince.code)[value]; _selectedDistrict = CityUtil.getCityModelByCode(_selectedCity.code).first; }); }, children: CityUtil.getCityModelByCode(_selectedProvince.code) .map((e) => Center( child: Text( e.name, style: TextStyle( fontSize: getFontSize(e.name), ), ))) .toList(), ), ), Expanded( child: CupertinoPicker( offAxisFraction: 0.6, looping: CityUtil.getCityModelByCode(_selectedCity.code).length > 1, itemExtent: 30, useMagnifier: true, magnification: 1.1, scrollController: _districtController, onSelectedItemChanged: (value) { _selectedDistrict = CityUtil.getCityModelByCode(_selectedCity.code)[value]; }, children: CityUtil.getCityModelByCode(_selectedCity.code) .map((e) => Center( child: Text( e.name, style: TextStyle( fontSize: getFontSize(e.name), ), ))) .toList(), ), ), ], ), ); } }